Oil and gas pipelines typically transport oil or gas at high temperatures, in order to facilitate flow of the oil or gas through the pipeline. These pipelines are typically insulated for efficiency.
Foamed insulation materials, which are material having hollow fillers embedded in a matrix (e.g., a polymer matrix), have been used to insulate pipes. The presence of hollow fillers, which may be glass, ceramic or polymer microspheres, results in hollow cells in the insulation material and improves thermal conductivity (i.e., lowers the k-value) of the insulation material.
There are challenges in the processing of such insulation materials and extrusion of such materials over pipes, including possible breakage of the hollow fillers during processing and extrusion, particularly in the case of glass or ceramic microspheres. Another possible challenge is the need for the matrix material to have relatively high melt strength during the extrusion process, to be able to form stable hollow cells during extrusion and processing. It may also be challenging to control the uniformity and/or density of cells in the insulation material.